1. Field of the Invention
The present invention relates to a driving support apparatus which is mounted in, for example, a vehicle and operable to output driving support information to a driver.
2. Description of the Background Art
Conventionally, there has been known a technology in which lane markings (so-called while lines) installed on right and left sides of a lane in which a vehicle is running are detected via a CCD (Charge Coupled Device) camera or the like and based on the detected lane markings, a driver is notified of driving support information in order to prevent a departure from the lane. However, in a case where the lane markings cannot be detected, it may occur that the driving support information cannot be accurately notified. In order to solve this problem, a variety of apparatuses, methods, and the like have been proposed (for example, refer to Japanese Patent Application Laid-Open Publication No. 2003-44836).
A partition line recognition apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2003-44836 has: an image processing part for extracting, from an image shot by a camera, white lines (which correspond to lane markings) painted on a road surface; and a white line estimation part for estimating, when the image processing part extracts either one of the white lines on the right or left side, a position of the other of the white lines, which is not extracted, based on coordinates of a plurality of sample points which are set on the extracted white line, based on road width calculation parameters which correspond to the sample points, and based on data of a road width of the lane in which the vehicle is running. This partition line recognition apparatus allows the other partition line to be estimated from the one partition line (white line or the like) which was allowed to be detected.
However, since in the partition line recognition apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2003-44836, the position of the lane marking on the side, which is not detected, is estimated based on the data of the road width of the lane in which the vehicle is running, and the like, it may occur that the position of the lane marking on the side, which is not detected, cannot be accurately detected. Specifically, in the partition line recognition apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2003-44836, based on the coordinates of the plurality of sample points, which are set on the extracted lane marking, and the road width calculation parameters corresponding to the sample points, and the data of the road width of the lane in which the vehicle is running, the position of the lane marking on the side, which is not detected, is estimated. Therefore, in a case where the road width calculation parameters, the data of the road width, and the like are not accurate, the position of the lane marking on the side, which is not detected, cannot be accurately estimated.
In addition, even in a state in which the lane marking can be accurately detected, there may be a case where it is preferable that the position of the lane marking, which is used for a purpose of, for example, preventing a departure from the lane, is set so as to be located more inward than the position estimated based on the position of the detected lane marking (namely, the real lane marking). Specifically, in a case where a sidewall made of concrete or the like, which is supposed to bring about devastating damage on a vehicle if the vehicle contacts the sidewall, is installed outside the detected lane marking, it is preferable that the position of the lane marking used for the purpose of preventing the departure from the lane is set so as to be located more inward than the position of the detected lane marking.